[Reconstruction of the aortic bifurcation: endovascular aortic repair (EVAR) and alternatives].

CLINICAL ISSUE: Diseases of the aortic bifurcation, whether stenotic or dilating, are mostly a manifestation of arteriosclerosis. If only stenosis is present aortic bifurcation disease is equivalent to a certain form of peripheral arterial occlusive disease (PAOD) characterized by the specific anatomical location. Aneurysmal disease and PAOD of the aortic bifurcation may occur together and men older than 60 years are particularly affected. The main symptom of aortic bifurcation PAOD is bilateral claudication whereas aneurysmal disease of the aortic bifurcation is frequently asymptomatic.

STANDARD TREATMENT: Therapy of stenotic and aneurysmal disease of the aortic bifurcation depends on the degree of the disease. Simple lesions, such as isolated stenoses of the aortic bifurcation or unilateral occlusions of the common iliac artery extending to the aortic bifurcation have been treated endoluminally for many years. Current standard treatment of complex aortic bifurcation disease is open surgery with implantation of an aortobifemoral bypass graft. However, recent developments in less invasive endoluminal methods have shifted the indications more towards endoluminal therapy. This development is mirrored by the international TransAtlantic Inter-Society Consensus (TASC) II recommendations from 2007 and even more clearly by the current national S3 guidelines on PAOD (https://www.degir.de/site/leitlinien). It is stated that in complex aortic bifurcation disease, such as bilateral occlusions of the common iliac arteries (TASC C lesions) or diffuse aortobiiliac stenoses and occlusions (TASC D lesions), endoluminal therapy may be considered as an alternative to open surgery. Therapy of aneurysmal disease of the aortic bifurcation depends on the pathoanatomical conditions. Prerequisite for endoluminal therapy is a sufficient landing zone for the prostheses. If this prerequisite is fulfilled endoluminal therapy is very likely comparable to open surgery with regard to technical and clinical success. Long-term results are still lacking.

DIAGNOSTIC WORK-UP: For the decision on the type of therapy and the sizing of the prostheses, thin-slice (≤ 3 mm slice thickness) computed tomography angiography (CTA) of the abdominal aorta and the iliac arteries including multiplanar reconstruction in the sagittal and coronal plane are sufficient. The inguinal arteries have to be included in the CTA volume.

PERFORMANCE: Compared to open surgery, endoluminal therapy of stenotic and aneurysmal disease of the aortic bifurcation has the advantage of reduced invasiveness. Hence patient recovery and hospital stay may be shorter.

ACHIEVEMENTS: Therapy of stenotic and aneurysmal disease of the aortic bifurcation is changing. Standard treatment of complex aortic bifurcation disease, which is open surgery is extended by the possibilities of endoluminal methods. Due to improvements in current endoluminal systems and development of new techniques, the importance of endoluminal therapy will further increase.

PRACTICAL RECOMMENDATIONS: Good quality of the preinterventional CTA is important for planning the intervention. In order for a radiologist to offer endoluminal therapy, besides knowledge of interventional skills a close cooperation with clinical colleagues, in particular vascular surgeons is mandatory.